Apparatus and method for manufacturing pouch, and method for manufacturing secondary battery

Abstract

The present invention relates to an apparatus for manufacturing a bag, the apparatus for manufacturing a bag including: a mold in which a pair of formation grooves having a partition wall therebetween is formed in a top surface of the mold, a bag film being disposed on the mold; and a pair of punches disposed above the mold to be respectively inserted into the pair of formation grooves while forming a pair of accommodation portions in the bag film in a state of pressing the bag film, wherein a pressing surface of each of the punches pressing the bag film has a tilt angle that is gradually tilted upward from one end disposed on one side of the partition wall toward the other end.

Description

Equipment and methods for manufacturing bags and methods for manufacturing secondary batteries

[0001] This application is a divisional application of the invention patent application with application number 201980003508.8, international application number PCT / KR2019 / 002389, international application date of February 27, 2019, and invention title "Apparatus and method for manufacturing bags and method for manufacturing secondary batteries".

[0002] Cross-reference to related applications

[0003] This application claims the benefit of priority to Korean Patent Application No. 10-2018-0026263, filed on March 6, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0004] This invention relates to an apparatus and method for manufacturing bags and a method for manufacturing secondary batteries, and more particularly to an apparatus and method for manufacturing bags capable of improving the quality of bags folded in the form of pockets and a method for manufacturing secondary batteries. Background Technology

[0005] Generally, unlike non-rechargeable primary batteries, secondary batteries are batteries that can be both recharged and discharged. Secondary batteries are widely used in high-tech electronic devices such as mobile phones, laptops, and portable video cameras.

[0006] Such secondary batteries are divided into can-type secondary batteries, in which the electrode assembly is built into a metal can, and pouch-type secondary batteries, in which the electrode assembly is built into a pouch. Pouch-type secondary batteries include an electrode assembly, an electrolyte, and a pouch containing the electrode assembly and the electrolyte. Furthermore, the electrode assembly has a structure in which multiple electrodes and multiple separators are alternately stacked.

[0007] The bag includes an upper housing and a lower housing. The upper housing and the lower housing include: an upper receiving portion and a lower receiving portion, respectively, which receive an upper portion and a lower portion of an electrode assembly in their central portions; a connecting portion that connects the sides of the upper receiving portion and the lower receiving portion to each other; and a sealing portion formed on the remaining surfaces of the upper receiving portion and the lower receiving portion, except for the connecting portion.

[0008] A method of manufacturing a bag having the above configuration includes: a forming step of forming an upper receiving portion and a lower receiving portion on two sides of a diaphragm sheet opposite to the center of the diaphragm sheet; and a bending step of bending a connecting portion disposed between the upper receiving portion and the lower receiving portion such that the upper receiving portion and the lower receiving portion correspond to each other.

[0009] Here, in the forming step, each of the upper receiving portion and the lower receiving portion is formed such that one end provided on one side of the connecting portion and the other end provided on the other side of the connecting portion have the same height.

[0010] However, in each of the upper and lower receiving portions, the elastic restoring force is mainly applied to one end of the connecting portion on one side rather than to the other end on the other side of the connecting portion, thus causing a height deviation and resulting in the production of defective products.

[0011] In other words, because one end of each of the upper and lower receiving portions is tensioned to bisecte the area of ​​the connecting portion, the elastic restoring force is applied relatively more to one end than the other. Therefore, there exists a problem where the elastic restoring force is applied relatively more to one end of each of the upper and lower receiving portions than the other, causing a height misalignment. Summary of the Invention

[0012] Technical issues

[0013] The present invention was made to solve the above-mentioned problems. The object of the present invention is to provide an apparatus and method for manufacturing a bag in which an upper receiving portion and a lower receiving portion are formed in a bag film, wherein the connecting portion connecting the upper receiving portion and the lower receiving portion to each other is formed such that one end of the connecting portion is higher than the other end of the side opposite to that end, thereby improving the quality of the bag, and a method for manufacturing a secondary battery.

[0014] Technical solution

[0015] To achieve the above objective, an apparatus for manufacturing bags according to a first embodiment of the present invention includes: a mold having a pair of forming grooves with a partition wall between them formed in the top surface of the mold, and a bag film disposed on the mold; and a pair of punches disposed above the mold to form a pair of receiving portions in the bag film while pressing the bag film, wherein each of the punches pressing the bag film has a pressing surface having an angle of inclination that gradually slopes upward from one end disposed on one side of the partition wall toward the other end.

[0016] The pressing surface of the punch may have an inclination angle of 2° to 10°.

[0017] The bottom surface of each of the forming grooves may have the same tilt angle as the pressing surface of the punch.

[0018] The device may further include: a punch holder having a pair of punches, wherein the punch holder allows the pair of punches to descend or ascend simultaneously.

[0019] The device may further include an adjustment section for connecting the punch to the punch holder, wherein the adjustment section connects the punch to the punch holder such that the angle of the pressing surface is adjustable.

[0020] The adjustment unit may include: a hinge pin that rotatably hinges one end of the punch to the punch holder; and an adjustment bolt that passes through the punch holder and is rotatably connected to the other end of the punch, and, depending on the direction of rotation, causes the other end to descend or rise toward the bag film to adjust the angle of the pressing surface.

[0021] A heating element for generating heat is built into the partition wall, and the heating element can heat the bag film disposed on the partition wall.

[0022] A method for manufacturing a bag according to a first embodiment of the present invention, the method comprising: step (a) disposing a bag film on the top surface of a mold in which a pair of forming grooves having a partition wall between them are formed; inserting a pair of punches, each having a pressing surface that gradually slopes upward from one end of the partition wall toward the other end, together with the bag film into the pair of forming grooves to form a pair of receiving portions in the bag film; and step (c) folding a fold formed between the pair of receiving portions such that the pair of receiving portions correspond to each other, wherein, in the receiving portion formed by step (b), the end of the receiving portion disposed on one side of the partition wall is formed to be deeper than the other end which is the opposite side of the one end.

[0023] Step (a) may include heating the bag film disposed on the partition wall to increase elongation.

[0024] Step (b) may include placing the bag film for a predetermined time after the pair of receptacles are formed, until the elasticity of the receptacles is fully restored.

[0025] A method for manufacturing a bag according to a second embodiment of the present invention, the method comprising: step (A) manufacturing a bag having a pocket shape; step (B) accommodating an electrode assembly in the bag; and step (C) sealing a sealing portion formed on the remaining sides of the bag except for a fold, wherein step (A) comprises: step (a) disposing a bag film on the top surface of a mold in which a pair of forming grooves having a partition wall between them are formed; inserting a pair of punches, each having an inclined surface that gradually slopes upward from one end of the partition wall toward the other end, together with the bag film into the pair of forming grooves to form a pair of receiving portions in the bag film; and step (c) folding the fold formed between the pair of receiving portions such that the pair of receiving portions correspond to each other, wherein, in the receiving portion formed by step (b), the end of the receiving portion disposed on one side of the partition wall is formed to be deeper than the other end which is the opposite side of the one end.

[0026] Beneficial effects

[0027] First, the bag manufacturing apparatus according to the present invention may include a mold on which a bag film is disposed, and a pair of forming grooves with a partition wall between them are formed in the mold. A punch is inserted into the forming grooves to form a receiving portion in the bag film, wherein the pressing surface of the punch performing the forming step of the bag film has an inclination angle that gradually slopes upward from one end disposed on one side of the partition wall toward the other end. Due to this feature, the forming step can be performed such that the end of the receiving portion disposed on one side of the partition wall has a higher height than the other end. Therefore, when the receiving portion is restored by an elastic restoring force, the heights of one end and the other end of the receiving portion can be adjusted to match each other equally. That is, because the forming step is performed such that one end of the receiving portion has a higher height than the other end, the heights of one end and the other end of the receiving portion can be adjusted to match each other equally.

[0028] Second: In the bag manufacturing apparatus according to the present invention, the pressing surface of the punch can have an inclination angle of 2° to 10°. That is, when the pressing surface of the punch has an inclination angle of 2° or less, because the inclination angle is small, the height difference between one end and the other end of the receiving portion is small. Therefore, it is impossible to match the heights of one end and the other end of the receiving portion equally. Moreover, when the pressing surface of the punch has an inclination angle of 10° or greater, the heights of one end and the other end of the receiving portion can be adjusted to match each other equally. However, one end of the receiving portion may be over-formed, causing cracks. Therefore, the pressing surface of the punch can have an inclination angle of 2° to 10°, so that the heights of one end and the other end of the receiving portion are stably adjusted to match each other equally.

[0029] Third: In the bag manufacturing apparatus according to the invention, the bottom surface of the forming groove formed in the mold can have the same inclination angle as the pressing surface of the punch. Due to this feature, the bag film disposed between the punch and the forming groove can be pressed to more accurately form the receiving portion in the bag film, thereby improving the quality of the bag.

[0030] Fourth: In the bag manufacturing apparatus according to the invention, a pair of punches can be disposed on a punch holder. Due to this feature, the pair of punches can descend or ascend simultaneously. Therefore, receptacles with the same shape can be formed in the bag film to improve the quality of the bag.

[0031] Fifth: The apparatus for manufacturing bags according to the invention may further include an adjusting portion for connecting a punch with an adjustable angle for its pressing surface to a punch holder. Due to this feature, the tilt angle of the pressing surface provided on the punch can be freely adjusted within the range of 2° to 10°, thus the heights of one end and the other end of the receiving portion can be stably adjusted to match each other equally.

[0032] Sixth: In the bag manufacturing apparatus according to the present invention, the adjusting part may include a hinge pin and an adjusting bolt. Due to this feature, the tilt angle of the pressing surface on the punch connected to the punch holder can be adjusted more precisely and easily, thereby improving work efficiency.

[0033] Seventh: In the bag manufacturing apparatus according to the present invention, a heating element for generating heat can be built into a partition wall provided on the mold. Due to this feature, the bag film provided on the partition wall can be heated to increase its elongation. Therefore, when a forming process is performed on the bag film, the forming process can be stably performed on the bag film provided on one side of the partition wall. Attached Figure Description

[0034] Figure 1 is a cross-sectional view of an apparatus for manufacturing bags according to a first embodiment of the present invention.

[0035] Figure 2 is a cross-sectional view illustrating the usage state of the bag manufacturing equipment according to the first embodiment of the present invention.

[0036] Figure 3 is a cross-sectional view illustrating the recovery state of a bag film manufactured by a bag manufacturing apparatus according to a first embodiment of the present invention.

[0037] Figure 4 is a cross-sectional view of a bag according to a first embodiment of the present invention.

[0038] Figure 5 is a cross-sectional view illustrating the heating component of the bag manufacturing apparatus according to the first embodiment of the present invention.

[0039] Figure 6 is a flowchart illustrating a method for manufacturing a bag according to a first embodiment of the present invention.

[0040] Figure 7 is a cross-sectional view of a secondary battery according to a second embodiment of the present invention.

[0041] Figure 8 is a cross-sectional view of an apparatus for manufacturing bags according to a third embodiment of the present invention. Detailed Implementation

[0042] Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings in a manner that allows those skilled in the art to readily implement the invention. However, the invention may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, for clarity, any unnecessary details used to describe the invention will be omitted, and the same reference numerals denote the same elements.

[0043] [Apparatus for manufacturing bags according to a first embodiment of the present invention]

[0044] As shown in Figures 1 and 2, the bag manufacturing apparatus 100 according to the first embodiment of the present invention includes: a mold 110, a pair of forming grooves 112 with a partition wall 111 between them formed in the top surface of the mold 110, and a bag film 10a disposed on the mold 110; and a pair of punches 120 disposed above the mold 110 to be inserted into the pair of forming grooves 112 while pressing the bag film 10a, and to form a pair of receiving portions 11 in the bag film 10a.

[0045] In other words, in the bag manufacturing apparatus 100 according to the first embodiment of the present invention, a bag film 10a is provided on the top surface of a mold 110, and then a pair of punches 120 descend. As a result, the pair of punches 120 are inserted into the forming groove 112 while pressing the bag film 10a, so as to form a receiving portion 11 in the bag film 10a.

[0046] As shown in Figure 3, in each of the receiving portions 11 formed in the bag film 10a, a relatively large restoring force is applied to one end 11a compared to the other end 11b, which is a receiving portion 11 and is disposed on the partition wall 111. Therefore, when one end 11a and the other end 11b of the receiving portion 11 are formed at the same height, the height between one end 11a and the other end 11b of the receiving portion 11 may be different due to the different restoring forces.

[0047] To prevent this phenomenon from occurring, the bag manufacturing apparatus 100 according to the present invention may have a structure for equally adjusting the height of one end 11a and the other end 11b of the receiving portion 11 having different restoring forces.

[0048] For example, referring to FIG1, the pressing surface 121 of the punch 120 of the pressing bag film 10a has an inclination angle that gradually slopes upward from one end 121a provided on one side of the partition wall 111 toward the other end 121b. Therefore, one end 11a of the receiving portion 11 can be formed to have a length greater than that of the other end 11b. As a result, as shown by the dashed line in FIG3, one end 11a and the other end 11b of the receiving portion 11 can be restored to match with equal heights.

[0049] More specifically, referring to the enlarged view of FIG2, when a forming process is performed on the bag film 10a provided on the mold 110 using the inclined pressing surface 121 to manufacture the receiving portion 11, one end 11a of the receiving portion 11 located on one side of the partition wall 111 can be formed with a length (or height) of "α", while the other end 11b can be formed with a length (or height) of "β". Therefore, one end 11a of the receiving portion 11 can be further formed with a length (or height) of "γ" compared to the other end 11b.

[0050] Additionally, as shown in Figure 3, when the bag film 10a manufactured by the bag manufacturing equipment 100 is placed for a predetermined time, a restoring force will occur. Here, one end 11a of the receiving portion 11 recovers more than the other end 11b, so a height difference may occur between one end 11a and the other end 11b of the receiving portion 11.

[0051] In summary, according to the first embodiment of the present invention, the bag manufacturing apparatus 100 may form one end 11a of the receiving portion 11 longer than the other end 11b, which is the opposite side of one end 11a. Therefore, the heights of one end 11a and the other end 11b of the receiving portion 11 can be matched equally to improve the quality of the bag.

[0052] The pressing surface 121 of the punch 120 has an inclination angle of 2° to 10°. That is, when the pressing surface 121 of the punch 120 has an inclination angle of 2° or less, because the inclination angle is small, the forming process can be performed, resulting in one end 11a of the receiving portion 11 having a height higher than the other end 11b, which is the opposite side of one end 11a. Therefore, the heights of one end 11a and the other end 11b of the receiving portion 11 cannot be matched equally. Moreover, when the pressing surface 121 of the punch 120 has an inclination angle of 10° or greater, one end 11a of the receiving portion 11 may be formed larger, causing cracks. Therefore, the pressing surface 121 of the punch 120 can have an inclination angle of 2° to 10° to ensure that the heights of one end 11a and the other end 11b of the receiving portion 11 are stably and equally matched.

[0053] In the bag manufacturing apparatus 100 according to the first embodiment of the present invention, the bottom surface 112a of the groove 112 corresponding to the pressing surface 121 of the punch 120 may have the same tilt angle as the pressing surface 121 shown in FIG1.

[0054] For example, referring to FIG1, the bottom surface 112a may have an inclination angle that gradually slopes upward from one end 112a-1 connected to the partition wall 111 toward the other end 112a-2 on the opposite side of the end 112a-1. Therefore, when the punch 120 is inserted into the forming groove 112 of the mold 110, the pressing surface 121 and the bottom surface 112a can be tightly attached to each other to stably press the bag film 10a, thereby precisely forming the receiving portion 11.

[0055] Here, the bottom surface 112a of the groove 112 can have a horizontal shape. That is, the bottom surface 112a of the groove 112 can have the same horizontal surface as the bag film 10a provided on the mold 110.

[0056] In the bag manufacturing apparatus 100 according to the first embodiment of the present invention, a pair of punches 120 are provided on a punch holder 130. That is, referring to FIG1, a pair of punches 120 may be provided on the bottom surface of the punch holder 130. Therefore, when the punch holder 130 is lowered or raised, the pair of punches 120 may be lowered or raised simultaneously, thereby forming a pair of receiving portions 11 in the bag film 10a simultaneously.

[0057] As shown in FIG5, in the bag manufacturing apparatus 100 according to the first embodiment of the present invention, a heating member 140 for generating heat is built into the partition wall 111. The heating member 140 may be provided on or closely attached to the partition wall 111 to heat the bag film 10a. That is, when the bag film 10a provided on one side of the partition wall 111 is subjected to a forming process using the punch 120, cracks may occur. In order to prevent cracks from occurring, the heating member 140 may be built into the partition wall 111, and the bag film 10a provided on or closely attached to one side of the partition wall 111 may be heated by the heating member 140 to increase the elongation. Therefore, when the forming process is performed on the bag film 10a provided on one side of the partition wall 111, the occurrence of cracks can be prevented.

[0058] A heating wire that generates heat when powered can be used as the heating element 140. Furthermore, the heating element 140 may further include a switch. The switch can turn the heating wire on or off. Additionally, the heating element 140 may further include a control unit. The control unit controls the temperature of the heating wire.

[0059] Therefore, as shown in FIG3, in the bag manufacturing apparatus 100 according to the first embodiment of the present invention, a pair of receiving portions 11 can be stably formed in the bag film 10a. In particular, the heights of one end 11a and the other end 11b of the receiving portions formed in the bag film 10a can be matched equally to each other.

[0060] Furthermore, in the bag film 10a in which the heights of one end 11a and the other end 11b of the receiving portion 11 are matched to each other, when the folding portion 12 disposed between the pair of receiving portions 11 is folded so that the pair of receiving portions 11 correspond to each other, a finished bag 10 can be obtained.

[0061] That is, a pair of receiving portions 11 can be formed in the center of the finished bag. In addition, a fold portion 12 can be formed on one side (the left surface when viewed in FIG4), and a sealing portion 13 can be formed on the other sides besides the fold portion 12.

[0062] Hereinafter, a method for manufacturing a bag using a bag manufacturing apparatus having the above-described structure according to a first embodiment of the present invention will be described.

[0063] [Method for manufacturing a bag according to a first embodiment of the present invention]

[0064] As shown in FIG6, the method for manufacturing a bag according to the first embodiment of the present invention includes: a step of setting a bag film (a); a step of forming a pair of receiving portions in the bag film (b); and a step of folding the folded portion formed between the pair of receiving portions (c).

[0065] Referring to FIG1, in step (a), a bag film 10a is placed on a mold 110 in which a pair of forming grooves 112 having a partition wall 111 between them are formed.

[0066] Referring here to FIG5, step (a) may further include heating the bag film 10a disposed on the partition wall 111 to increase elongation. That is, the heating member 140 is built into the partition wall 111. The heating member 140 can generate heat when powered to heat the bag film 10a disposed on or tightly attached to the partition wall 111, thereby increasing the temperature. Therefore, the bag film 10a disposed on the partition wall 111 can increase its elongation.

[0067] Referring to Figure 2, in step (b), the punch holder 130 disposed above the mold 110 descends. Therefore, a pair of punches 120 disposed on the bottom surface of the punch holder 130 can descend together and then be inserted into a pair of forming grooves 112 while the bag film 10a is pressed. Thus, a receiving portion 11 can be formed in the bag film 10a.

[0068] Here, as shown in FIG1, the pressing surface 121 of the pressing bag film 10a of the punch 120 is formed with an inclination angle that gradually slopes upward from one end 121a on one side of the partition wall 111 toward the other end 121b. Therefore, the receiving portion 11 is formed such that the end 11a of the receiving portion on one side of the partition wall 111 has a height greater than the height of the other end 11b on the opposite side of that end 11a.

[0069] Here, as shown in FIG3, step (b) further includes placing the bag film 10a, in which the receiving portion 11 is formed, for a predetermined time. Therefore, a portion of the formed receiving portion 11 is restored. Here, one end 11a of the receiving portion 11 is restored to a greater extent than the other end 11b, so as to equally match the heights of one end 11a and the other end 11b of the receiving portion 11.

[0070] The preset time can range from 1 minute to 10 minutes. This means that if the preset time is less than 1 minute, the film bag may not fully recover. If the preset time is greater than 10 minutes, even if the film bag recovers fully, it may consume excessive working time, thus reducing processability. Therefore, the preset time can be set within the range of 1 to 10 minutes to improve work efficiency.

[0071] Step (b) may further include a defect inspection step to check whether a defect has occurred by measuring and comparing the heights of one end 11a and the other end 11b of the receiving portion 11.

[0072] In other words, referring to the enlarged view in Figure 2, during the defect inspection step, the receiving portion 11 formed in the bag film 10a is photographed, and the length of each of one end 11a and the other end 11b of the receiving portion 11 is measured using the photographed image of the receiving portion 11. Here, when the difference γ between the measured length α of one end 11a and the measured length β of the other end 11b is within a set range, it is determined to be normal; and when the difference γ is not within the set range, it is determined to be defective.

[0073] The setting range can be from 0.1mm to 5.0mm, particularly from 0.5mm to 2.0mm. That is, when the setting range is less than 0.1mm, the accuracy must be increased, thus reducing work efficiency. When the setting range is greater than 5.0mm, the height difference between one end 11a and the other end 11b of the receiving portion 11 may be large, leading to defective products. Therefore, the setting range can be set to 0.1mm to 5.0mm, particularly from 0.5mm to 2.0mm, thereby improving the quality of the bag film.

[0074] Referring to FIG4, in step (c), the folded portion 12 formed between the pair of receiving portions 11 is folded so that the pair of receiving portions 11 correspond to each other. Thus, the finished bag 10 can be obtained.

[0075] In the following description of another embodiment of the invention, components having the same configuration and function as those in the above embodiment are given the same reference numerals in the drawings, and therefore repeated descriptions will be omitted.

[0076] [Method for manufacturing a secondary battery according to a second embodiment of the present invention]

[0077] As shown in FIG7, the method for manufacturing a secondary battery according to the second embodiment of the present invention may include: a step (A) of manufacturing a bag 10 having a pocket shape; a step (B) of accommodating an electrode assembly 20 in the bag 10; and a step (C) of sealing the sealing portions formed on the remaining sides of the bag 10 except for the folded portion 12 of the bag 10. The above steps can be used to manufacture a finished secondary battery 1.

[0078] Here, step (A) includes: step (a) placing a bag film on the top surface of a mold in which a pair of forming grooves with a partition wall are formed; step (b) inserting a pair of punches, each having an inclined surface that gradually slopes upward from one end of the partition wall toward the other, together with the bag film into the pair of forming grooves to form a pair of receiving portions in the bag film; and step (c) folding the folded portion formed between the pair of receiving portions so that the pair of receiving portions correspond to each other. In the receiving portion formed by step (b), the end of the receiving portion located on one side of the partition wall is formed to be deeper than the other end on the opposite side of that end.

[0079] Step (A) is the same as the method for manufacturing bags described above, therefore its detailed description will be omitted.

[0080] Therefore, in the method of manufacturing a secondary battery according to the second embodiment of the present invention, a bag with one end of the receiving portion and the other end, which is the opposite side of the receiving portion, can be provided to manufacture the secondary battery 1, thereby significantly improving the quality of the secondary battery 1.

[0081] [Apparatus for manufacturing bags according to a third embodiment of the present invention]

[0082] The apparatus for manufacturing bags according to a third embodiment of the present invention is provided as another example of an apparatus for manufacturing bags according to the aforementioned first embodiment of the present invention.

[0083] In other words, as shown in FIG8, the bag manufacturing apparatus 100 according to the third embodiment of the present invention includes an adjustment unit 150, which connects the punch 120 to the punch holder 130 such that the angle of the pressing surface provided on the punch 120 is adjustable. Therefore, the angle of the pressing surface 121 provided on the punch 120 can be adjusted according to the thickness and material of the bag film 10a, thereby matching the heights of one end 11a and the other end 11b of the receiving portion 11 formed in the bag film 10a equally.

[0084] For example, as shown in FIG8, the adjustment part 150 includes: a hinge pin 151, which rotatably hinges one end 121a of the punch 120 to the punch holder 130; and an adjustment bolt 152, which passes through the punch holder 130 to rotatably connect the other end 121b of the punch 120, and lowers or raises the other end 121b toward the bag film 10a according to the rotation direction, so as to adjust the angle of the pressing surface 121.

[0085] In other words, the adjustment section 150 can raise or lower the other end 121b of the punch 120 according to the rotation direction of the adjustment bolt 152, so as to adjust the angle of the pressing surface 121 relative to the bag film 10a.

[0086] The adjustment unit 150 can adjust the pressing surface 121 so that the pressing surface 121 on each of the pair of punches 120 provided on the punch holder 130 has an angle of inclination relative to the bag film 10a; or adjust the pressing surface 121 so that the pressing surface 121 has the same horizontal surface as the bag film 10a.

[0087] Therefore, the scope of this invention is defined by the appended claims, rather than by the foregoing description and the exemplary embodiments described therein. Various modifications made within the scope of the claims and their equivalents are considered to be within the scope of this invention.

Claims

1. An apparatus for manufacturing bags, the apparatus comprising: A mold having a pair of forming grooves with partition walls between them formed in the top surface of the mold, and a bag film disposed on the mold; A pair of punches are disposed above the mold to be inserted into the pair of forming grooves while the bag film is being pressed, thereby forming a pair of receiving portions in the bag film. Each of the punches pressing the bag film has a pressing surface having an angle of inclination that gradually slopes upward from one end of the partition wall toward the other end. A heating element for generating heat is built into the partition wall and heats the bag film disposed on the partition wall.

2. The device according to claim 1, wherein the pressing surface of the punch has an inclination angle of 2° to 10°.

3. The device according to claim 1, wherein the bottom surface of each of the forming grooves has the same inclination angle as the pressing surface of the punch.

4. The device of claim 1, further comprising a punch holder having a pair of punches, wherein the punch holder causes the pair of punches to descend or ascend simultaneously.

5. The device of claim 4, further comprising an adjusting portion for connecting the punch to the punch holder, wherein the adjusting portion connects the punch to the punch holder such that the angle of the pressing surface is adjustable, wherein the adjusting portion includes: A hinge pin that rotatably hinges one end of the punch to the punch holder; An adjusting bolt, which passes through the punch holder and is rotatably connected to the other end of the punch, and, depending on the direction of rotation, causes the other end to descend or rise toward the bag film to adjust the angle of the pressing surface.

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